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iir. 



DtKETOXES DEr.IYED FEOM DIACETOEESOECIXOL- 

 DDIETHYLETHEE. 



By JOSEPH ALGAE, M.Sc, 

 University College, Dublin. 



Read Mat 22. Published July 7, 1916. 



Ix a paper by Eyan and O'Neill (Proc. Eoyal Irish Acad., xxxii (1915), B, 

 p. 48) two syntheses of diflavone are described. The first consisted of the 

 preparation of dibenzylidene-diacetoresorcinol which was then acetylated 

 and brominated. By tliis means was obtained the tetrabromide of dihydroxy- 

 diehalkone-diacetate which, wben warmed with alcoholic potash, gave 

 diflavone. In the second synthesis diacetoresorcinol- dime thy lether was 

 condensetl with benzoic est€r. and the dike tone thus formed was heated 

 with concentrated hydriodic acid. In this manner diflavone was again 

 obtained. 



Using the first method, attempts were made by Eyan and Algar (Proc. 

 Eoyal Irish Acad., x.xxii (1915 1, B, p. 185) and by Ryan and Walsh 

 {ibid., p. 193) to obtain other diflavone derivatives from dianisylideiie- 

 diacetoresorcinol and diveratrylidene-diacetoresoreinol. The reaction, how- 

 ever, gave dieoumaranone derivatives in each case instead of diflavone 

 derivatives. The present research was undertaken with a view to preparing 

 diflavone derivatives by the second method. Diketones are described which 

 were obtained by the condensation of diacetoresorcinol- dimethy lether with 

 anisic, phenyl-acetic, acetic, and oxalic esters. The condensations with anisic 

 and phenyl-acetic esters both gave small yields of the diketone, consequently 

 it was impossible to test the action of hot concentrated hydriodic acid on 

 these diketones. The diketones obtained from acetic and oxalic estei's were 

 formed in larger quantities, and the action of concentrated hydriodic acid on 

 these compounds was investigated. In both cases the results were extremely 

 unsatisfactory, the products being either resins or non-crystallisable oils. 

 On prolonged heating of diacetylacetoresorcinol-dimethylether with hydriodic 

 acid and purification of the product, a very small quantity of a colourless 

 substance was isolated, which dissolved in concentrated sulphmie acid, the 

 solution having the strong, green fluorescence characteristic of chromone 



